As is well known, mobile land communications and the like suffer from an undesirable phenomena called Rayleigh fading in which there are wide fluctuations in the strength of the received electromagnetic wave signals due to the influence on wave propagation of building structures and the relatively short 1-4 meter height of the antennas on vehicles. Various diversity reception methods have been used to ameliorate these fluctuations in the received electromagnetic signal. These include such techniques as automatic switching among several antennas, automatic selection from among several receivers, and the combining of signals from several receivers. See, for example, the discussion of basic diversity classifications and combining methods in the book Microwave Mobile Communications, William C. Jakes, Jr., editor, published by John Wiley & Sons, Inc. (New York 1974), particularly at pages 309-321.